With the improvement of people's living standard, digital technologies are developing towards audiovisual products, and high-quality sounder products have been used by ordinary families. A multi-channel sounder has a higher quality sound effect. A channel level difference (channel level difference, CLD) is an important parameter that represents a multi-channel signal sound field, and reflects an energy relationship in each frequency band between two signals of the multi-channel signals. The CLD is widely applied in current multi-channel signal coding algorithms, for example, intensity multi-channel signal coding algorithm, parameter multi-channel signal coding algorithm, and Panning algorithm. The CLD needs to be quantized by a scalar quantizer. The scalar quantizer is a 31-dimensional vector code book CLDs, where CLDs=[−50, −45, −40, −35, −30, −25, −22, −19, −16, −13, −10, −8, −6, −4, −2, 0, 2, 4, 6, 8, 10, 13, 16, 19, 22, 25, 30, 35, 40, 45, 50]. The size of the code book is 5 bits. The CLDs of all frequency bands in a data frame are quantized according to the vector code book CLDs, and each element in the CLDs represents the quantization level of the CLD.
During the process of implementing the present invention, the inventor discovers that the prior art has at least the following disadvantages: Because the coder needs to quantize all CLD of stereo speech signals, the complexity of quantizing the CLDs is increased, and the efficiency of quantizing the CLDs is reduced.